People today use multiple digital devices which are interconnected by various kinds of LAN (Local Area Network) and PAN (Personal Area Network) technologies. UPnP™ (Universal Plug and Play) and DLNA® (Digital Living Network Alliance) are standards focusing on the media consumption within home LANs, and allow users to play for example media stored in their network accessed storage (NAS) on a TV set in their living room. Furthermore, people have multiple portable devices and gadgets that are getting connected by LAN and PAN technologies while walking on the streets. At the same time, a lot of services are available in the Internet, offered by service providers or even by the user's own home networks, accessible through WAN (Wide Area Network) technologies. Numerous video sharing sites are available on the Internet. Also, many Internet radio stations are available, and Podcast sites offer audio and video together with well-formed meta-data.
As described in US20050210155, a service provider may expose the service in a residential network, a LAN for example, in the form of a virtual device. FIG. 1 illustrates an information processing system 100 to provide a virtual device. A LAN 110 is a residential network of a user 160, including an IG (IMS Gateway) 111 and a local device 113. The local device 113 connects an IMS (IP Multimedia Subsystem) environment 120 via the IG 111. The IMS environment 120 includes a PNAS 121 to create a virtual device as a composition of multiple services provisioned by a service provider (SP) 130. The virtual device implements one or more virtual services 112 provided by the IG 111. The IG 111 announces the virtual service 112 for the LAN 110 using a protocol supported there such as UPnP. The local device 113 can obtain a description of the service profile provided by the IG 111 and access to the service profile. The access to the virtual service 112 is translated to an access to the PNAS 121, and the result returned by the service provider 130 is again translated to the protocol supported by the LAN 110 and returned to the local device 113.
The PNAS 121 collects the context information from the LAN 110 and exposes the context information to service providers and end users. The context information contains the capability of the local device 113, sensors and actuators in the LAN 110 and services provided by them. It is updated when there is some event occurred in the local device 113 or a status in the local device 113 has changed. The IG 111 works as an intermediary entity to publish the context information towards the PNAS 121 in the secure and effective manner.
The IMS environment 120 may provide the user 160 with a remote access to the LAN 110. The user 160 accesses to services in the LAN 110 remotely using a user equipment 150. A service provider 140 provides the user equipment 150 with this remote access. The service provider 140 retrieves the service description of the virtual service 112 from the PNAS 121 and presents this service description to the user equipment 150. When the service provider 140 receives a request for the virtual service 112 from the user equipment 150, the service provider 140 transfers this request to the IG 111 after appropriate protocol conversions. The IG 111 executes the virtual service 112 and returns the result to the user equipment 150.
To execute the virtual service 112, the IG 111 requires the native service provisioned by the service provider 130. That is, the request from the user equipment 150 traversed the path of the service provider 140, the IG 111, and the service provider 130, and the response traverses the return path. This causes a trombone routing and the user 160 may experience a long latency.